Experimental and numerical analysis of diluted combustion in a direct injection CNG engine featuring post- Euro-VI fuel consumption targets
The present paper is concerned with part of the work performed by Renault, IFPEN and Politecnico di Torino within the Gason research project (H2020 framework of the EC). More precisely, the overall objectives of the project mainly consist in the reduction of the carbon footprint through the mitigation of the CO2 emissions, as well as in the reinforcement of alternative fuels so as to progressively decrease the dependence on crude oil. Accordingly, the Gason WP4 is focused on the development of a dedicated CNG engine featuring a 25% decrease in fuel consumption with respect to an equivalent Diesel engine with the same performance targets. To that end, based on the previous experience of the partners in the Mogador and InGAS projects, the present work has been primarily devoted to the optimization and implementation of different breakthrough technologies in the Gason engine, namely, direct injection, variable valve timing, LP EGR with advanced turbocharging, and diluted combustion.
Investigation into the Potentials of a Dedicated Multi-Point Injection System for a production NG Single-Point Heavy-Duty Engine
CNG is at present retaining a growing interest as a factual alternative to traditional fuels for SI engines, thanks to its high potentials in reducing the engine-out emissions. Increasing thrust into the exploitation of NG in the transport field is in fact produced by the even more stringent emission regulations that are being introduced into the worldwide scenario. The present paper aims at deeply investigating into the potentials of a heavy-duty engine running on CNG and equipped with two different injection systems, an advanced single point (SP) one and a prototype multi-point (MP) one. The considered 7.8-liter engine was designed and produced to implement a SP strategy and hence modified to run with a dedicated MP system. A thorough comparison of the engine equipped with the two injection systems has been carried out at steady state as well as at transient operations.